圆铝合金管混凝土短柱轴压力学性能与承载力计算模型研究

Research on mechanical properties and bearing capacity calculation models of concrete-filled circular aluminum alloy tubular stub columns under axial compression

摘要:

为明晰铝合金管混凝土的工作机理,验证并提升圆铝合金管混凝土短柱轴压承载力计算模型的可靠性,本文对现有圆铝合金管混凝土的短柱轴压试验进行了统计和分析,建立了试验数据库。在此基础上进一步分析了其短柱轴压力学性能,验证了现有5种典型承载力计算模型的适用性,并提出了更为准确的短柱轴压承载力计算模型。研究结果表明:现有研究的部分参数已超出“组合结构”的研究范畴,在相应分析中应予以单独考虑；相比于同条件的钢管混凝土,铝合金管混凝土的界限约束效应系数更高,初步可取为1.75；本文所列举的5种典型计算模型均可较好地预测圆铝合金管混凝土的短柱轴压承载力,但所收集试件中仍有5.6%~32.4%的承载力预测偏差超过20%,且主要集中于低约束效应系数（ξ<1.0）范围内；本文所提出的承载力计算模型对所收集试件的承载力预测偏差大于20%的占比低于3%。

Abstract:

This study aims to clarify the working mechanism of concrete-filled circular aluminum alloy tubular columns andverify/improve the reliability of the bearing capacity calculation models. The available experimental tests for concrete-filled circular aluminum alloy tubular stub columns under axial compression were collected and analyzed in this paper, with the experimental database established. The mechanical properties of the concrete-filled circular aluminum alloy tubular stub columns under axial compression were further investigated, and the applicability of the existing five typical bearing capacity calculation models was evaluated. A new calculation model with higher accuracy for predicting the compressive bearing capacity of concrete-filled circular aluminum alloy tubular stub columns was proposed. The investigated results indicate that some of the test variables of the existing studies may be beyond the scope of “steel-concrete composite structures”, which should be analyzed individually. The boundary confinement factor of concrete-filled circular aluminum alloy tubular columns is higher than that of conventional concrete-filled circular steel tubular columns under the same condition which can be taken as 1.75, approximately. The five typical existing calculation models can be used to provide an approximate prediction of the compressive bearing capacity of concrete-filled circular aluminum alloy tubular stub columns. However, there are still 5.6% to 32.4% of the collected specimens with predicted deviations exceeding 20%, which are mainly concentrated in the range of lower confinement factors (ξ<1.0). The proportion of the collected test specimens with deviations beyond 20% in the compressive bearing capacity predicted by the proposed calculation model in this paper is less than 3%.